The present invention is directed to an ink jet printing apparatus and, in particular, to an ink jet printing apparatus having an improved nozzle construction which provides for a multi-nozzle head with multiplex drive which requires fewer component parts. The ink jet printing apparatus of the present invention includes an ink-on-demand-type ink jet print head having a highly integrated multi-nozzle.
It is desirable to provide ink-on-demand type ink jet print heads with multiple nozzles to thereby highly integrate the nozzle. Such highly integrated print heads have been put to practical use in printing devices. However, where the number of nozzles is increased with higher integration in an ink jet print head, the increment of piezoelectric elements, wires and drive transistors corresponding to the nozzles is increased. This results in an increase in cost and higher complexity of a printer incorporating such a highly integrated ink jet print head.
Various proposals have been advanced for reducing problems encountered in integrated ink jet print heads. Several such proposals are described in U.S. Pat. No. 4,104,645 issued on Aug. 1, 1978. As described in detail hereinbelow, such constructions suffer from several disadvantages such as difficulty in fabrication and difficulty in disposing the nozzle orifices in close proximity. Accordingly, it is desired to provide an improved ink jet printing apparatus having a highly integrated multiple nozzle construction which avoids the problems encountered in prior art constructions.